High pressure fluid jet systems for cutting tissue and removing bone are known in the art. Fluid jet cutters focus pressurized fluid to impact desired target tissue and thereby emulsify the tissue. The tissue can then be suctioned or otherwise removed from the surgical site. While current fluid jet cutters are effective, when the fluid jet system is submerged in a liquid environment, such as water, the fluid jet interacts with the surrounding liquid, resulting in a reduction of the strength or cutting power of the fluid jet.
Various techniques have been used to address this problem. One of the earliest attempts to improve the performance of fluid jet cutters was to use a sheath around the jet such that the jet could travel through air in a fluid environment. The air allows the fluid to flow at a faster rate and at a greater distance, improving the efficiency of the device when used in a liquid environment. While the air shroud was shown to improve efficiency, there are additional disadvantages that come with this improved efficiency, including visualization and environmental disturbances when the air interacts with the surrounding fluid.
Accordingly, there is a need for improved devices and methods for cutting tissue using a high pressure fluid jet, preferably while minimizing the interaction between the fluid jet and the surrounding liquid environment.